This investigation will describe and analyze the epidemiology of neurodevelopmental and other childhood disabilities in disadvantaged and culturally diverse populations. A large and unique data set on six types of disability (mental retardation, epilepsy, movement disorders, speech disorders, blindness and deafness) is available for the study from community surveys recently completed in Bangladesh, Jamaica and Pakistan. All three countries employed a common two-stage study design and identical research instruments and data base programs. At stage I all children in the communities were screened and at stage II children with positive screening results plus samples of children with negative screening results were examined by a physician and psychologist teams. Screening and risk factor data are available for more than 22,000 children and detailed clinical data are available for approximately 7,200 children. Using this data set, the proposed five-year research plan has five specific aims. The first aim is to evaluate the reliability and validity in different cultures of research methodology designed to screen for disabilities in 2 to 9 year-old children, to collect data on risk factors for disability and to make diagnostic assessments. The plan is to identify the questions and test items that appear reliable and valid across all three countries. The second aim is to use the screening and clinical data to obtain estimates of the prevalence of childhood disability in the communities studied. The third aim is to investigate the major causes and risk factors for childhood disability in the communities surveyed. The proportion of disabilities among surviving children that might have been prevented by interventions such as nutritional supplements (e.g., iodine, vitamin A), immunizations, sanitation, and trauma prevention devices will be estimated. The fourth aim is to use the findings from this study to obtain insights into the needs and resources for rehabilitation and special care of disabled children in the less developed world. The fifth aim is to develop plans to apply the methods developed in this study to research in under-served and culturally diverse communities within the United States.